As one might expect, this has significant effects on how the theory is to be interpreted. Indeed, one question that is common when discussing the foundations of quantum mechanics is, what is the interpretation of the quantum state \(\Psi \) ? Is the wave function an element of the ontology? That is to say, is it a “real" object, like a particle or a field? Or, is the wave function epistemic, related to our state of knowledge of the system? Clearly in ED the answer is the latter, and as a result, interpretations of quantum mechanics where the wave function is given an ontic status are dismissed outright; such interpretations include the Bohmian theory [1]}[2]} and the provocative “Many-Worlds" interpretations first proposed by Everett [3]}.
